Question: Solve for $x$ and $y$ using substitution. ${-2x+6y = -10}$ ${y = 5x-11}$
Answer: Since $y$ has already been solved for, substitute $5x-11$ for $y$ in the first equation. ${-2x + 6}{(5x-11)}{= -10}$ Simplify and solve for $x$ $-2x+30x - 66 = -10$ $28x-66 = -10$ $28x-66{+66} = -10{+66}$ $28x = 56$ $\dfrac{28x}{{28}} = \dfrac{56}{{28}}$ ${x = 2}$ Now that you know ${x = 2}$ , plug it back into $\thinspace {y = 5x-11}\thinspace$ to find $y$ ${y = 5}{(2)}{ - 11}$ $y = 10 - 11$ $y = -1$ You can also plug ${x = 2}$ into $\thinspace {-2x+6y = -10}\thinspace$ and get the same answer for $y$ : ${-2}{(2)}{ + 6y = -10}$ ${y = -1}$